This study explored the effect of length of pregnancy on the
induction-to-abortion interval of medical second trimester abortion.
Information was collected retrospectively on a consecutive series of 270
women with pregnancies of 12 to 22.6 weeks, who underwent abortion in
Barcelona, Spain, from April 2006 to June 2009. All the women received a
single oral dose of 200 mg mifepristone and 36-48 hours later, a course
of misoprostol (an initial vaginal dose of 800 mcg plus four oral doses
of 400 mcg at three-hourly intervals). The mean length of pregnancy was
18 weeks. The mean induction-to-abortion interval was 9.8 hours, and 91%
of the women aborted successfully within 24 hours. Length of pregnancy
(p<0.001) and parity (p<0.003) were the only two variables
independently associated with the induction-to-abortion interval. The
mean induction-to-abortion interval was 12.9 hours in those beyond 20
weeks of pregnancy, about four hours longer than for those who were
12-20 weeks pregnant. The proportion of women over 20 weeks of pregnancy
who aborted within 12 hours was 59%, compared to 81% who were at 12-20
weeks. The nulliparous women needed longer, a mean of l0.1 hours,
compared to women with a previous live birth (8.1 hours). This
information is relevant for counselling and planning of second trimester
medical abortions. (1)